Heat Controller VMH09SC-1, VMH12SC-1, VMH24SC-1, VMH18SC-1 service manual E3 Indoor or E7 Outdoor

Service Manual VMH Series Heat Controller, Inc.

E2:

9.2.3 Zero crossing check resistance or inverter compressor, it is .7Ω error

Alarm signal when the main chip can’t detect over-zero signal. When such failure occurs, the main control board must have fault.

Turn off the power supply for 5 seconds, then turn it back on.

Check power supply and

connections

Yes

Indoor PCB defective

No

Correct power supply or

correct connections

Shut off the power supply and turn on it		E3: INDOOR OR E7 OUTDOOR
		9.2.4 Fan speed has been out of control diagnosis
	The unit does not work normally

Turn off the unit, rotate the cross fan. Does it rotate

Yes

Is the fan motor connector and connection good?

Yes

Is voltage being applied to the fan motor?

No

Yes

Disassemble the connection between fan and motor, check bearing. If bad, change the bearing. If ok, follow the below

Replace the fan motor

No

Replace the PCB

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